package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * @author ck
 * @date 2021/10/14 15:48
 */
@RestController
@RequestMapping("/common")
@Slf4j
@Api(tags = "通用相关接口")
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    @PostMapping("/upload")
    @ApiOperation("图片上传接口")
    public R<String> upload(MultipartFile file){
        //file是一个临时文件需要转存到指定位置，否则本次请求完成后临时文件会被删除
        log.info(file.toString());

        //原始文件名
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名，防止文件名称重复造成文件覆盖
        String filename = UUID.randomUUID().toString() + suffix;
        //创建一个目录对象
        File dir = new File(basePath);
        //判断当前目录是否存在
        if (!dir.exists()){
            //文件不存在，需要创建
            dir.mkdirs();
        }
        //将临时文件转存到指定位置
        try {
            file.transferTo(new File(basePath+filename));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(filename);
    }

    @GetMapping("/download")
    @ApiOperation("图片下载接口")
    public void download(String name, HttpServletResponse response){

        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fis = new FileInputStream(new File(basePath + name));
            //输出流，通过输出流文件写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();

            byte[] bytes = new byte[1024];
            int len = 0;
            while ((len = fis.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //释放资源
            fis.close();
            outputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}
